Step 9: Postprocessing for the Mixture Solution

Graphics and Animations

1.   Display the static pressure field in the tee (Figure  20.3).

Graphics and Animations Contours Set Up...

(a)   Enable Filled in the Options group box.

(b)   Retain the default selection of Pressure... and Static Pressure from the Contours of drop-down lists.

(c)   Click Display.

Figure 20.3: Contours of Static Pressure

2.   Display contours of velocity magnitude (Figure  20.4).

Graphics and Animations Contours Set Up...

(a)   Select Velocity... and Velocity Magnitude from the Contours of drop-down lists.

(b)   Click Display.

Figure 20.4: Contours of Velocity Magnitude

3.   Display the volume fraction of air (Figure  20.5).

Graphics and Animations Contours Set Up...

(a)   Select Phases... and Volume fraction from the Contours of drop-down lists.

(b)   Select air from the Phase drop-down list.

(c)   Click Display and close the Contours dialog box.

Figure 20.5: Contours of Air Volume Fraction

  When gravity acts downwards, it induces stratification in the side arm of the tee junction. In Figure  20.5, you can see that the gas (air) tends to concentrate on the upper part of the side arm. In this case, gravity acts against inertia that tends to concentrate gas on the low pressure side, thereby creating gas pockets. In the vertical arm, the gas travels upward faster than the water due to the effect of gravity, and therefore there is less separation. The outflow split modifies the relation between inertia forces and gravity to a large extent, and has an important role in flow distribution and on the gas concentration.